luas daerah yg di arsir adalah a.226,08cm2 c.362,66cm2 b.441,25 cm2 d.411,75cm2

Luas Persegi Panjang = p × l
= 21 × 28
= 588 cm^2

Luas setengah lingkaran
= 1/2 × phi × r^2
= 1/2 × 22/7 × 10,5^2
= 1/2 × 22/7 × 110,25
= 1/2 × 22 × 15,75
= 11 × 15,75
= 173,25 cm^2

Luas Arsiran = Luas persegi panjang - luas setengah lingkaran
= 588 cm^2 - 173,25 cm^2
= 414,75 cm^2

=> Jawaban D

L1(persegi panjang)=p×l
=21×28=588cm2
L2(setengah lingkaran=1/2×1/4(phi)d2
=1/2×1/4×22/7×21×21
=1/2×1/4×22×3×21
=1/2×1/4×66×21
=1/2×1/4×1386
=173.25cm2

Larsiran=L1-L2
=588-173.25
=414.75cm2
Jawaban : D